This book is based on "interviews with 50 couples who are still together, and still {consider themselves} happy, after years of marriage. Most of the book is concerned with defining the four types of marriages (romantic, rescue, companionate, and traditional) that Wallerstein discovered through her interviews. . . . The rest of the book outlines nine developmental tasks--derived from Wallerstein's practice {as a clinical psychologist} as well as the interviews--that couples need to accomplish if their marriage is to be a happy one."